Side impact events involving automotive vehicles typically include the imposition of dynamic loading to the vehicle body sides. The side impact event imposes severe loading on the structural members of the body. This situation is complicated by the fact that many compact or mid-sized vehicles have low rocker heights that may pass below the bumper of an impacting vehicle, resulting in high door velocities.
Although automotive bodies used in conventional body-on-frame construction have typically used cross members for decades, such cross members have not been involved in the management of crash-related energy. In essence, with a more typical construction, the space between the inner rocker panel and the end of the underbody cross members must first be closed by plastic deformation of the sheet metal bridging between these two structures. This sheet metal is usually flat and comprises a portion of the floor pan.
In an effort to allow the side structure to react in a more controlled manner against laterally imposed loads, transverse tube structures have been provided between the rocker and the tunnel. In the event of a side impact the load is passed to the center of the vehicle. The vehicle front seat is typically attached to the tube structure. This arrangement created a package problem for occupant foot space in the rear seat. On the other hand, if the structure is part of the seat then gaps are required between the structure in the seat and the B-pillar and the center console. This arrangement does not effectively take a load until after the deformation of the vehicle occurs.
Accordingly, as in so many areas of vehicle safety technology, there is room in the art for further advancement in the design of vehicle side structures.